Pouch-type battery cell including venting member and battery pack including the same

ABSTRACT

A pouch-type battery cell includes a battery case including a metal layer and polymer resin layer, and an electrode assembly disposed within the battery case, the battery case further including an electrode assembly receiving part formed in at least one of an upper case and a lower case of the battery case, and a venting member disposed on an outer surface of the electrode assembly receiving part at a location adjacent to a sealing part of the battery case, wherein the venting member is made of a shape memory alloy that is deformed to penetrate the battery case when a temperature of the venting member increases to a value above a transition temperature of the shape memory alloy. A battery module including the pouch-type battery cell, and a battery pack are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase entry under U.S.C. § 371 ofInternational Application No. PCT/KR2019/016541, filed Nov. 28, 2019,published in Korean, which claims the benefit of priority to KoreanPatent Application No. 10-2018-0157169 filed on Dec. 7, 2018, thedisclosures of which are hereby incorporated by reference herein theirentireties.

TECHNICAL FIELD

The present invention relates to a pouch-type battery cell including aventing member and a battery pack including the same. Specifically, thepresent invention relates to a pouch-type battery cell and, and abattery pack including the same, the pouch-type battery cell capable ofinducing the venting of a battery cell by adding a venting member madeof a shape memory alloy material on an outer surface of the pouch-typebattery cell, or an inner surface of an battery pack case including thepouch-type battery cell.

BACKGROUND ART

As an energy source capable of repeatedly charging and dischargingportable electronic products such as mobile phones, tablet PCs, andvacuum cleaners, the demand for secondary batteries is rapidlyincreasing. Research and development of secondary batteries forapplication to devices requiring high capacity and high efficiency, suchas electric vehicles and power storage devices, are in progress.

In particular, among secondary batteries, lithium secondary batterieshaving advantages such as high energy density, high voltage, high power,and excellent life characteristics are widely used.

The lithium secondary batteries may be classified based on the shape ofa case. For example, there is a cylindrical battery or a prismaticbattery, each of the cylindrical battery and the prismatic battery isconfigured to have an electrode assembly mounted in a metal can, andthere is a pouch-type battery, the pouch-type battery is configured tohave an electrode assembly mounted in a pouch-type case made of analuminum laminate sheet. The pouch-type battery has an advantage that itcan freely change in shape because it can be easily curved or bent.

In general, a lithium secondary battery includes an electrode activematerial, a binder, and an electrolyte constituting an electrode as maincomponents, which are electrochemically stable at operating voltagesranging from 2.5V to 4.3V. However, when the voltage of the lithiumsecondary battery rises above the operating voltage, the components aredecomposed to generate gas, and thus the lithium secondary battery isexpanded and deformed due to the generated gas. In addition, when aseparator is damaged by an inorganic material included in the electrodemixture, contact between a positive electrode and a negative electrodemay cause a large amount of current to flow and promote the generationof heat and gas, which may cause ignition and explosion of the secondarybattery.

In order to remove the gas generated inside the battery, the cylindricalbattery and the prismatic battery are provided with a safety device suchas a vent in a cap assembly, while the pouch-type battery onlydetermines venting by the sealing strength without a separate safetydevice. However, there is a problem that it is difficult to guideventing under desired conditions.

In this regard, Korean Patent No. 0886570 discloses a secondary batteryin which an opening communicating with an interior is formed in abattery case and a safety opening and closing portion of a shape memoryalloy capable of opening and closing the opening is added.

Korean Patent No. 0886570 uses a structure for opening and closing theopening in a pouch case of the state in which the opening was formed.However, since the safety opening and closing portion is applied to asealing part of the pouch battery, there is a problem that a dead spaceoccurs in the width direction of the battery cell because a structure inwhich the sealing part is bent is not applicable.

Korean Patent Application Publication No. 2013-0019477 relates to asecondary battery having a form of opening through a pouch while abent-shape of shape memory alloy is being unbent when the temperaturerises.

However, Korean Patent Application Publication No. 2013-0019477 is notpreferable because the shape memory alloy is located inside thepouch-type battery, and there is a problem that the shape memory alloygenerates side reactions with the electrolyte and the like.

As such, in order to discharge the gas generated inside the pouch-typebattery cell at a desired temperature, there is an urgent need for atechnology that can set the discharge temperature of the gas and canprevent the ignition and explosion caused by the increased internalpressure of the secondary battery.

DISCLOSURE Technical Problem

The present invention has been made in view of the above problems, andit is an object of the present invention to provide a pouch-type batterycell capable of discharging gas in the battery cell at a desiredtemperature by applying a venting member made of a shape memory alloy onan outer surface of the pouch-type battery cell.

Technical Solution

In accordance with the present invention, the above and other objectscan be accomplished by the provision of a pouch-type battery cellcomprising a battery case including a metal layer and a polymer resinlayer, and an electrode assembly disposed within the battery case,wherein the battery case may further include an electrode assemblyreceiving part formed in at least one of an upper case and a lower caseof the battery case, and a venting member disposed on an outer surfaceof the electrode assembly receiving part at a location adjacent to asealing part of the battery case, the venting member made of a shapememory alloy that is deformed to penetrate the battery case when atemperature of the venting member increases to a value above atransition temperature of the shape memory alloy.

The venting member may be formed in a straight shape when thetemperature of the venting member is at or below the transitiontemperature, and at least one end of the venting member may be bent whenthe temperature of the venting member is above the transitiontemperature.

A deformed portion of the venting member may have a pointed end.

The electrode assembly receiving part is formed in both the upper caseand the lower case; the electrode assembly may be a unidirectionalelectrode assembly in which electrode terminals are formed in onedirection; and the location at which the venting member may be disposedon the outer surface of the electrode assembly receiving part isadjacent to the sealing part where the electrode terminals are disposed.

The electrode assembly receiving part is formed in both the upper caseand the lower case; the electrode assembly may be a bidirectionalelectrode assembly in which electrode terminals are formed in bothdirections; and the location at which the venting member may be disposedon the outer surface of the electrode assembly receiving part isadjacent to the sealing part where the electrode terminals are disposedor adjacent to the sealing part where the electrode terminals are notdisposed.

The location at which the venting member may be disposed on the outersurface of the electrode assembly receiving part in a direction in whichthe electrode terminal is not disposed is among side surfaces of theelectrode assembly receiving part.

The venting member may be disposed between a bent sealing part of thebattery case and a side surface of the electrode assembly receiving partfacing the bent sealing part.

The present invention also provides a battery module including one ormore pouch-type battery cells, wherein the battery module may includethe one or more pouch-type battery cells, a housing configured toreceive the one or more pouch-type battery cells, and a venting memberconfigured to discharge internal gas in at least one of the one or morepouch-type battery cells. The venting member may be attached to aposition on an inner surface of the housing facing the sealing part ofat least one of the one or more pouch-type battery cells.

The position to which the venting member may be attached faces thesealing part in a direction in which electrode terminals of thepouch-type battery cell are disposed.

The position to which the venting member may be attached faces thesealing part in a direction in which electrode terminals of thepouch-type battery cell are not disposed.

The present invention also provides a battery pack configured to receivethe pouch-type battery cell or a battery module including the pouch-typebattery cell therein, in which the battery pack may include a ventingmember configured to penetrate a battery case of the pouch-type batterycell by deforming its shape due to a change of temperature, the ventingmember being added to an end plate coupled to electrode terminals of thepouch-type battery cell or a cooling fin contacting the pouch-typebattery cell.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing venting members before and afterdeformation of the venting members.

FIG. 2 is a perspective view showing a pouch-type battery cell includinga unidirectional electrode assembly and an electrode assembly receivingpart formed only in an upper case.

FIG. 3 is a plan view showing a pouch-type battery cell including abidirectional electrode assembly.

FIG. 4 is an exploded perspective view showing a pouch-type battery cellincluding a unidirectional electrode assembly and an electrode assemblyreceiving part formed in an upper case and a lower case.

FIG. 5 is a perspective view showing a pouch-type battery cell includinga bidirectional electrode assembly and having an electrode assemblyreceiving part formed only in an upper case.

FIG. 6 is a perspective view showing a pouch-type battery cell in whicha sealing part is bent.

FIG. 7 is an exploded view showing a battery pack including a pouch-typebattery cell and a venting member.

BEST MODE

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings suchthat the preferred embodiments of the present invention can be easilyimplemented by those skilled in the art to which the present inventionpertains. In describing the principle of operation of the preferredembodiments of the present invention in detail, however, a detaileddescription of known functions and configurations incorporated hereinwill be omitted when the same may obscure the subject matter of thepresent invention.

In addition, the same reference numbers will be used throughout thedrawings to refer to parts that perform similar functions or operations.In the case in which one part is said to be connected to another part inthe specification, not only may the one part be directly connected tothe another part, but also, the one part may be indirectly connected tothe another part via a further part. In addition, that a certain elementis included does not mean that other elements are excluded, but meansthat such elements may be further included unless mentioned otherwise.

A pouch-type battery cell according to the present invention maycomprise a battery case including a metal layer and a polymer resinlayer, wherein the battery case may include an electrode assemblyreceiving part formed on at least one of an upper case and a lower case,and a venting member disposed on an outer surface of the electrodeassembly receiving part, which is an adjacent portion of a sealing partof the battery case, and the venting member made of a shape memory alloythat is deformed to penetrate the battery case when the temperature ofthe battery cell increases.

The battery case may be configured to have a structure including anouter resin layer made of a material that is not affected by theexternal environment; a metal layer for preventing inflow of gas andmoisture and for preventing leakage of electrolyte; and an inner resinlayer for sealing the battery case.

The electrode assembly may be classified into a jelly-roll type (woundtype) electrode assembly, which is configured to have a structure inwhich long sheet type positive electrodes and long sheet type negativeelectrodes are wound in the state in which separators are interposedrespectively between the positive electrodes and the negativeelectrodes, a stacked type electrode assembly, which is configured tohave a structure in which a plurality of positive electrodes cut so asto have a predetermined size and a plurality of negative electrodes cutso as to have a predetermined size are sequentially stacked in the statein which separators are interposed respectively between the positiveelectrodes and the negative electrodes, a stacked/folded type electrodeassembly, which is configured to have a structure in which bi-cells orfull cells, each of which is configured to have a structure in whichpredetermined numbers of positive electrodes and negative electrodes arestacked in the state in which separators are disposed respectivelybetween the positive electrodes and the negative electrodes, are woundusing a separation sheet, or a laminated/stacked type electrodeassembly, which is configured to have a structure in which bi-cells orfull cells are stacked and laminated in the state in which separatorsare disposed respectively between the bi-cells or the full cells.

The electrode assembly may be configured to have only one type ofelectrode assembly, or may be configured to have two or more types ofelectrode assemblies having different shapes.

When the electrode assemblies are configured to have two or more typesof electrode assemblies, the electrode assembly receiving part may havea stepped structure in consideration of the fact that the size of theelectrode assemblies may be different from each other on a plane.

The venting member may be made of a shape memory alloy, which is a metalalloy having a property of returning to its original shape beforedeformation when it is above the transition temperature, even if thedeformation state is maintained at or below the transition temperature.The shape memory alloy may typically be made of a titanium-nickel-basedalloy or a copper-zinc-aluminum-based alloy.

The venting member may be formed in a straight shape at a normaltemperature, and at least one end thereof may be bent when thetemperature increases. Thus, as the venting member is bent in an inwarddirection of the battery case, a through hole is formed in the batterycase to discharge gas.

Hereinafter, a normal temperature form of a venting member is referredto as a deformed form (state), and returning to the form of the ventingmember before deformation above the transition temperature is referredto as a recovered form (state).

In order to easily form a through hole for discharging gas, the ventingmember may have a pointed shape at the end of the portion to be deformedand recovered.

In this regard, FIG. 1 shows a perspective view of venting membersbefore and after deformation of the venting members.

Referring to FIG. 1 , a venting member 10 has a generally thincylindrical shape, and is deformed in a straight form at a normaltemperature. However, when the venting member 10 is above the transitiontemperature, a right end of the venting member 10 is bent because theventing member 10 is recovered to the form before deformation.

The venting member 10 has a flat left end that does not bend above thetransition temperature, while the right end of the venting member 10 isbent at a temperature above the transition temperature and has a pointedshape. Therefore, it is advantageous to form a through hole in thebattery case.

A venting member 20 has a generally thin cylindrical shape, and isdeformed in a straight form at a normal temperature. However, when theventing member 20 is above the transition temperature, both ends of theventing member 20 are bent in the same direction because the ventingmember 20 is recovered to the form before deformation.

The venting member 20 is formed in a pointed shape at the left and rightends that are bent when it is above the transition temperature.

A venting member 30 has a generally thin and flat rectangular pillarshape, and is deformed in a straight form at a normal temperature.However, when the venting member 30 is above the transition temperature,a right end of the venting member 30 is bent because the venting member30 is recovered to the form before deformation.

The venting member 30 has a flat left end that does not bend above thetransition temperature, while the right end of the venting member 30 isbent above the transition temperature and has a pointed shape.Therefore, it is advantageous to form a through hole in the batterycase.

When the venting member according to the present invention becomes in arecovered form in a state where it is bent from a straight deformedform, a portion of the venting member penetrates through the batterycase and is bent into the battery cell. Thus, a space for receiving thebent venting member inside the battery cell is required.

For example, when a stacked type electrode assembly is used as theelectrode assembly, the space where an electrode tab and an electrodelead connecting part are positioned may be used as a space for receivingthe bent venting member.

As a first embodiment according to the present invention, FIG. 2 shows aperspective view of a pouch-type battery cell including a unidirectionalelectrode assembly and an electrode assembly receiving part formed onlyin the upper case.

Referring to FIG. 2 , a pouch-type battery cell 100 has a structure inwhich a sealing part of outer edges of an upper case 110, in which anelectrode assembly receiving part 111 is formed, and a sealing part ofouter edges of a lower case 120 of a flat shape are sealed.

The electrode assembly receiving part 111 is configured to receive aunidirectional electrode assembly in which a positive electrode terminal101 and a negative electrode terminal 102 are formed in one direction. Aventing member 131 is disposed on an outer surface of the electrodeassembly receiving part 111, which is an adjacent portion of a sealingpart 141 where the positive electrode terminal 101 and the negativeelectrode terminal 102 are disposed.

The venting member 131 may have a structure of any one of the ventingmembers shown in FIG. 1 and becomes a recovered form as one end or bothends of the venting member are bent toward the battery case above thetransition temperature. A through hole is formed in the battery case bythe venting member which is in the recovered form, and internal gas ofthe battery cell can be discharged through the through hole.

However, it is preferable that the end of the bent venting member 131 isnot in contact with the electrode terminals. Therefore, when using theunidirectional electrode assembly as shown in FIG. 2 , the ventingmembers 10 and 30, which are bent such that only one end thereof becomesthe recovered form, may be used and the bent end of the venting member131 may be received in the internal space of the battery cell disposedbetween the positive electrode terminal 101 and the negative electrodeterminal 102.

As a second embodiment according to the present invention, FIG. 3 showsa plan view of a pouch-type battery cell including a bidirectionalelectrode assembly.

Referring to FIG. 3 , a pouch-type battery cell 200 is configured tohave an electrode assembly receiving part 211 formed in an upper case210, and the electrode assembly receiving part 211 is configured toreceive a bidirectional electrode assembly in which a positive electrodeterminal 201 and a negative electrode terminal 202 protrude in oppositedirections.

A lower case of the pouch-type battery cell 200 may be a flat shape ormay have a structure in which an electrode assembly receiving part isformed.

A venting member 231 is disposed on an outer surface of the electrodeassembly receiving part 211, which is an adjacent portion of a sealingpart 241 where the positive electrode terminal 201 is disposed. Aventing member 232 is disposed on an outer surface of the electrodeassembly receiving part 211, which is an adjacent portion of a sealingpart 242 where the negative electrode terminal 202 is disposed.

The venting member 231 may have a structure of any one of the ventingmembers shown in FIG. 1 and becomes a recovered form as one end or bothends of the venting member are bent toward the battery case above thetransition temperature. A through hole is formed in the battery case bythe venting member which is in the recovered form, and internal gas ofthe battery cell can be discharged through the through hole.

When the pouch-type battery cell includes the bidirectional electrodeassembly as shown in FIG. 3 , it is preferable that a plurality ofexhaust ports are formed so that internal gas of the battery cell can bedischarged quickly. Thus, the venting members 231 and 232 may apply arecovered form such that both ends thereof are bent, as shown in theventing member 20 of FIG. 1 . The bent ends of the venting members 231and 232 may be received in the internal space of the battery celldisposed between the positive electrode terminal 201 and the negativeelectrode terminal 202.

The pouch-type battery cell 200 of FIG. 3 may have a structure in whichan electrode assembly receiving part is formed in the lower case. Insuch case, venting members may be additionally added to each of an outersurface of the electrode assembly receiving part formed in the lowercase, which is an adjacent portion to the sealing portion 241 where thepositive electrode terminal 201 is disposed and an outer surface of theelectrode assembly receiving part formed in the lower case, which is anadjacent portion of the sealing portion 242 where the negative terminal202 is disposed.

When the electrode assembly receiving part is formed in each of theupper case and the lower case, the size of the electrode assembly may beincreased, and thus gas generation due to internal side reactions in thebattery cell may increase. Therefore, rapid exhaust can be achieved byadding the venting members to the upper case and the lower case,respectively. Moreover, when using a venting member in which both endsare deformed in a recovered form, such as the venting member 20 of FIG.1 , it is preferable to obtain a fast exhaust effect since the number ofexhaust ports is increased.

As a third embodiment according to the present invention, FIG. 4 showsan exploded perspective view of a pouch-type battery cell including aunidirectional electrode assembly and an electrode assembly receivingpart formed in an upper case and a lower case, respectively.

Referring to FIG. 4 , a pouch-type battery cell 300 is configured tohave an electrode assembly receiving part 311 formed in an upper case310 and an electrode assembly receiving part 321 formed in a lower case320. The pouch-type battery cell 300 has a structure in which theunidirectional electrode assembly in which a positive electrode terminal301 and a negative electrode terminal 302 protrude in the same directionis received therein.

A venting member 331 is disposed on an outer surface of the electrodeassembly receiving part 311 of the upper case 310, which is an adjacentportion of a sealing part 341 where the positive electrode terminal 301and the negative electrode terminal 302 are disposed. A venting member332 is disposed on an outer surface of the electrode assembly receivingpart 321 of the lower case 320, which is an adjacent portion of thesealing part 341 where the positive electrode terminal 301 and thenegative electrode terminal 302 are disposed.

As the pouch-type battery cell 300 uses the unidirectional electrodeassembly, the venting members 331 and 332, such as the venting member131 of FIG. 2 , use a venting member in which only one end thereof isbent in a recovered form. The ends of the bent venting members 331 and332 may be received in the battery cell internal space disposed betweenthe positive electrode terminal 301 and the negative electrode terminal302.

As in the pouch-type battery cells of FIGS. 2 to 4 , when a ventingmember is disposed on an outer surface of an electrode assemblyreceiving part, which is an adjacent portion of a sealing part in adirection in which electrode terminals are disposed, the venting memberis disposed in a deformed state at the adjacent portion of a sealingpart where the electrode terminals are formed, and a bent portion of theventing member in a recovered state is received in a portion treated asdead space inside the battery cell. Thus, the problem of increasing thesize of the battery cell can be prevented due to the addition of theventing member.

As a fourth embodiment according to the present invention, the ventingmember may be disposed on an outer surface of an electrode assemblyreceiving part in a direction in which electrode terminals are notdisposed.

In this regard, FIG. 5 shows a perspective view of a pouch-type batterycell including a bidirectional electrode assembly and having anelectrode assembly receiving part formed only in an upper case.

Referring to FIG. 5 , a pouch-type battery cell 400 may have anelectrode assembly receiving part 411 formed on an upper case 410, and alower case 420 may be a flat shape or may have a structure in which theelectrode assembly receiving part is formed.

In the pouch-type battery cell 400, the electrode assembly receivingpart 411 is configured to receive a bidirectional electrode assembly inwhich a positive electrode terminal 401 and a negative electrodeterminal 402 protrude in opposite directions.

One or more venting members 431 may be disposed on outer surfaces of theelectrode assembly receiving part 411 of the upper case 410, which areadjacent portions of sealing parts 441 and 442 where the positiveelectrode terminal 401 and the negative electrode terminal 402 are notdisposed.

On the other hand, when an electrode assembly receiving part is formedin the lower case 420, a venting member may be additionally disposed onan outer surface of the electrode assembly receiving part of the lowercase 420, which is an adjacent portion of the sealing parts 441 and 442where the electrode terminals are not disposed.

Moreover, in addition to the venting member 431 disposed adjacent to thenegative terminal 402, a venting member may be further added to aposition adjacent to the positive electrode terminal 401 which issymmetrical thereto.

Unlike the venting members shown in FIGS. 2 to 4 , the venting members431 are disposed at the adjacent portions of the sealing parts whereelectrode terminals are not disposed, and thus it is preferable thatonly the ends of the venting members 431 in a direction close to theelectrode terminals are in a recovered form. In addition, the ends ofthe recovered venting member may be received in the battery cellinternal spaces disposed at both sides of the positive electrodeterminal 401 and the negative electrode terminal 402.

In addition, the venting members 431 may be disposed on outer surfacesof the electrode assembly receiving part 411 of the upper case 410,which are adjacent portions of the sealing parts where the positiveelectrode terminal 401 and/or the negative electrode terminal 402 aredisposed.

As a fifth embodiment according to the present invention, the ventingmember may be disposed between a bent sealing part of a battery case anda side surface of an electrode assembly receiving part facing the bentsealing part.

In this regard, FIG. 6 shows a perspective view of a pouch-type batterycell in which a sealing part is bent.

Referring to FIG. 6 , a pouch-type battery cell 500 is configured tohave an electrode assembly receiving part 511 formed in an upper case510, and an electrode assembly receiving part 521 formed in a lower case520. The pouch-type battery cell 500 has a structure in which aunidirectional electrode assembly in which a positive electrode terminal501 and a negative electrode terminal 502 protrude in the same directionis received therein.

The pouch-type battery cell 500 is in a state in which a sealing part ina direction in which the electrode terminals do not protrude is bent,and thus a venting member 531 is disposed between a bent sealing part540 and a side surface of the electrode assembly receiving part 521 ofthe lower case 520.

The venting member 531 has the same shape as the venting member 431 ofFIG. 5 , and thus only an end in a direction in which the negativeelectrode terminal 502 is disposed is in a recovered form that canpenetrate the battery case.

In addition, a venting member may be further disposed between theopposite side of the bent sealing part 540 and the side surface of theelectrode assembly receiving part. The end of the recovered ventingmember 531 may be received in the battery cell internal space outsidethe positive electrode terminal 501 and the negative electrode terminal502.

In the case of the pouch-type battery cell 500, although the ventingmember is not disposed at an adjacent portion of a sealing portion 541in a direction in which the electrode terminals are disposed, theventing member is disposed between the bent sealing part and the sidesurface of the electrode assembly receiving part. Thus, it is preferableto apply a thin and flat rectangular pillar-shaped venting member 30such as the venting member 30 of FIG. 1 .

The method of adding the venting member is not particularly limited aslong as the venting member may be stably fixed to the outer surface ofthe pouch-type battery cell. For example, an adhesive material may beapplied to the outer surface of the venting member to be attached, or anapparatus capable of physically mounting the venting member may be addedand fixed.

Specifically, the venting member may be attached using an adhesive tape,or a groove or the like for inserting the venting member may be used bymolding the pouch case. A method of attaching or physically fixing theventing member on the sealing part by using a separate member such as aclip for fitting the venting member to the pouch case or the electrodeterminals may be used.

The present invention also provides a battery module including thepouch-type battery cell, wherein the battery module may include thepouch-type battery cell, a housing configured to receive one or morepouch-type battery cells, and a venting member configured to dischargegas in the pouch-type battery cell. The venting member may be attachedto a position facing a sealing part of the pouch-type battery cell,which is an inner surface of the housing. In addition, it is possible tomanufacture and use a housing including a structure for fitting theventing member into the inner surface of the housing or inserting theventing member to be mounted on the inner surface of the housing.

Specifically, the venting member may be attached or fixed to a positionfacing a sealing part in a direction in which electrode terminals of thepouch-type battery cell are disposed, or a position facing a sealingpart in a direction in which electrode terminals of the pouch-typebattery cell is not disposed.

In this regard, FIG. 7 shows an exploded view of a battery moduleincluding a pouch-type battery cell and a venting member.

Referring to FIG. 7 , the battery module includes a pair of housings 651and 652 surrounding an outer surface of a pouch-type battery cell 600. Aventing member 631 is disposed at a position facing a sealing part 642in a direction in which electrode terminals of the pouch-type batterycell 600 are not disposed, which is an inner surface of the housing 651.

In addition, unlike what is shown in FIG. 7 , the battery moduleaccording to the present invention may have a form in which a ventingmember is added to an inner surface of a housing facing a sealing part641 in a direction in which electrode terminals are disposed.

The vent member 631 may be bent toward the pouch-type battery cell 600at the transition temperature to be in a recovered form, and thus, athrough hole for discharging gas may be formed in the battery case byrecovering the venting member.

As shown in FIG. 7 , since the venting member is added to a portiontreated as dead space inside the battery module, which is an adjacentportion of the pouch-type battery cell, the size of the battery modulemay be prevented from being changed due to the addition of the ventingmember.

The present invention also provides a battery pack configured to receivethe pouch-type battery cell or a battery module including the sametherein, in which a venting member penetrating a battery case of thepouch-type battery cell by deforming its shape due to a change oftemperature may be added to an end plate coupled to an electrodeterminal of the pouch-type battery cell or a cooling fin contacting thepouch-type battery cell.

In addition, the venting member may be fixed by mounting a groove, aring, a clip, or the like to an inner surface of the housing, the endplate, or the cooling fin.

As such, the venting member is not a structure added to the outersurface of the pouch-type battery cell, and may be attached to the endplate or the cooling fin located adjacent to the pouch-type batterycell. Thus, when the venting member becomes in a recovered state abovethe transition temperature, a through hole for discharging gas may beformed in the battery case while the venting member is being bent towardthe pouch-type battery cell.

The structure of the end plate and the cooling fins is not particularlylimited, and a structure that does not affect the overall size of thebattery pack may be applied even if the venting member is applied to astructure that does not affect the overall size.

As such, since a venting member included in the pouch-type battery cellaccording to the present invention is made of a shape memory alloy, theventing member may be designed to deform its shape at a temperaturerequiring gas discharge of the pouch-type battery cell.

As described above, the present invention includes a venting member ofthe shape memory alloy material, it is possible to prevent the explosionand ignition of the battery cell by venting at a desired temperature.

Those skilled in the art to which the present invention pertains willappreciate that various applications and modifications are possiblebased on the above description, without departing from the scope of thepresent invention.

DESCRIPTION OF REFERENCE NUMERALS

10, 20, 30, 131, 231, 232, 331, 332, 431, 531, 631: Venting members

100, 200, 300, 400, 500, 600: Pouch-type battery cells

101, 201, 301, 401, 501: Positive electrode terminals

102, 202, 302, 402, 502: Negative electrode terminals

110, 210, 310, 410, 510: Upper cases

111, 211, 311, 321, 411, 511, 521: electrode assembly receiving parts

120, 320,420, 520: Lower cases

141, 241, 242, 341, 541, 641: Sealing parts where electrode terminalsare disposed

441, 442, 642: Sealing parts where electrode terminals are not disposed

540: Bent sealing part

651, 652: Housings

INDUSTRIAL APPLICABILITY

As described above, a pouch-type battery cell according to the presentinvention can be discharged by forming a through-hole in a battery caseat a desired temperature.

In addition, by adding a venting member to the outside of the batterycell, it is possible to prevent a problem that the venting memberdisposed inside the battery cell causes side reactions with electrolyteand the like.

In addition, since a venting member is added to the surplus space of thebattery cell, it is possible to prevent the battery cell from increasingin size due to the addition of the venting member.

The invention claimed is:
 1. A pouch-type battery cell, comprising abattery case comprising a metal layer and a polymer resin layer, and anelectrode assembly disposed within the battery case, wherein the batterycase further comprises: an electrode assembly receiving part formed inat least one of an upper case and a lower case of the battery case, anda venting member disposed on only an outer surface of the electrodeassembly receiving part at a location adjacent to a sealing part of thebattery case, wherein the venting member is made of a shape memory alloythat is deformed to penetrate the battery case when a temperature of theventing member increases to a value above a transition temperature ofthe shape memory alloy.
 2. The pouch-type battery cell according toclaim 1, wherein the venting member is formed in a straight shape whenthe temperature of the venting member is at or below the transitiontemperature, and at least one end of the venting member is bent when thetemperature of the venting member is above the transition temperature.3. The pouch-type battery cell according to claim 1, wherein a deformedportion of the venting member has a pointed end.
 4. The pouch-typebattery cell according to claim 1, wherein the electrode assemblyreceiving part is formed in both the upper case and the lower case, theelectrode assembly is a unidirectional electrode assembly in whichelectrode terminals are formed in one direction, and the location atwhich the venting member is disposed on the outer surface of theelectrode assembly receiving part is adjacent to the sealing part wherethe electrode terminals are disposed.
 5. The pouch-type battery cellaccording to claim 1, wherein the electrode assembly receiving part isformed in both the upper case and the lower case, the electrode assemblyis a bidirectional electrode assembly in which electrode terminals areformed in both directions, and the location at which the venting memberis disposed on the outer surface of the electrode assembly receivingpart is adjacent to the sealing part where the electrode terminals aredisposed.
 6. The pouch-type battery cell according to claim 1, whereinthe location at which the venting member is disposed on the outersurface of the electrode assembly receiving part is among side surfacesof the electrode assembly receiving part in a direction in whichelectrode terminals are not disposed.
 7. The pouch-type battery cellaccording to claim 1, wherein the venting member is disposed between abent sealing part of the battery case and a side surface of theelectrode assembly receiving part facing the bent sealing part.
 8. Thepouch-type battery cell according to claim 1, wherein the electrodeassembly receiving part is formed in both the upper case and the lowercase, the electrode assembly is a bidirectional electrode assembly inwhich electrode terminals are formed in both directions, and thelocation at which the venting member is disposed on the outer surface ofthe electrode assembly receiving part is adjacent to the sealing partwhere the electrode terminals are not disposed.
 9. A pouch-type batterycell, comprising a battery case comprising a metal layer and a polymerresin layer, and an electrode assembly disposed within the battery case,wherein the battery case further comprises: an electrode assemblyreceiving part formed in at least one of an upper case and a lower caseof the battery case, and a venting member disposed on an outer surfaceof the electrode assembly receiving part at a location adjacent to asealing part of the battery case, wherein the venting member is made ofa shape memory alloy that is deformed to penetrate the battery case whena temperature of the venting member increases to a value above atransition temperature of the shape memory alloy, and wherein the entireventing member is formed in a straight shape when the temperature of theventing member is at or below the transition temperature, and at leastone end of the venting member is bent when the temperature of theventing member is above the transition temperature.